1. Field of Invention
The present invention relates to a printer system that includes a computer and a printer connected to the computer through a network or other channel, and a control method for the printer system enabling the computer to detect print jobs that have been completed (finished) on the printer. The invention also relates to a printer that enables the computer to easily detect print jobs that have been completed on the printer.
2. Description of Related Art
Printer systems that have a computer and one or more printers connected through a network, and are configured so that the computer acquires the operating status of each printer at a regular interval in order to ensure the reliability and operating status (working status) of the printer system, are known from the literature. In such a printer system, the computer sends a status data request to each printer at a regular interval in order to acquire status data indicating the operating status of each printer, and each printer that receives the status data request gets and returns status data indicating its own operating state to the computer. The printers return information about the operating state of the printer, such as a print state indicating a print job is being executed, a standby state indicating a print job is not being executed, and error states that occur when, for example, the ink runs out, as the status data.
The status data is information that is acquired at the moment the printer determines its own operating status in response to the status data request. As a result, if a status data request is sent from the computer immediately after the computer sends a print job to the printer, the printer returns status data indicating a standby state in response to this status data request, and the computer receives this status data report, it is difficult for the computer to detect if the reported standby state represents a standby state following completion of the print job that was just sent, or a standby state preceding the start of the print job.
In order for the computer to know if a print job sent to the printer has already been completed or has not yet been started, the computer could conceivably identify the individual print jobs and query the printer about the status of a particular print job. For example, with the printer system taught in Japanese Unexamined Patent Appl. Pub. JP-A-2009-83387, an ID value is assigned to each print job, and the computer can use the ID value to query the printer about the status of a particular print job. When such a query is received, the printer references a print job history that is updated and stored each time a print job is executed to get and send the status of the print job identified by the ID value to the computer.
When the computer must individually identify print jobs and query a printer to know if a particular print job sent to a printer has been completed, the number of transactions and communications between the computer and printers increases, and the load on the computer, printers, and network increases.